The present invention relates to plasma display panels and, more particularly plasma display panels using phosphors for converting discharge light emission to visible light.
Recently, up-conversion phosphors have been developed as novel phosphor. As mentioned in Japanese Patent Laid-Open No. 7-297475, the up-conversion phosphor absorbs infrared radiation and emits visible light by converting the absorbed infrared rays. Presently, this phosphor is mainly applied to infrared laser detection. Japanese Patent Laid-Open No. 9-54562 also discloses a plasma display using up-conversion phosphor, which is irradiated by an infrared laser beam to produce display.
The structure and function of a usual plasma display panel will now be briefly described with reference to FIG. 4. FIG. 4 is a fragmentary schematic sectional view shown in the structure of a prior art plasma display panel of reflecting type. The illustrated plasma display panel comprises a glass substrate 3 with discharge electrodes 1 and 2 formed thereon, and a glass substrate 5 with a write electrode 4 formed thereon. These substrates 3 and 5 face each other via partitioning walls 6 defining spaces between them. The spaces are filled with discharge gas, for instance xenon (Xe) gas. A conventional phosphor layer 7 is formed between adjacent parallel partitioning walls 6 on the glass substrate 5. Each of the spaces is filled with a gas, for instance Xe, as discharge gas having a vacuum ultraviolet radiation zone. By applying a high voltage between the discharge electrodes 1 and 2, electric discharge is brought about between the electrodes 1 and 2 to generate vacuum ultraviolet radiation, which causes light emission form the conventional phosphopr layer 7 formed on the glass substrate 5.
The prior art plasma display panel has a problem that its brightness is low. This is so because the vacuum ultraviolet radiation for causing light emission from the conventional phosphor layer 7 is generated with low efficiency by the electric discharge in the Xe gas. Accordingly, when realizing a display with the prior art plasma display panel, the frequency of the discharge light emission is increased to obtain brightness that is necessary for the display. Increasing the discharge light emission frequency, however, has drawback that power consumption and heat generation are increased and reduce the life of the panel.